CGRG Bibliography of Canadian Geomorphology
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Author : Geertsema, M.; and Clague, J.J.
Date : 2006.
Title : 1000-year record of landslide dams at Halden Creek, northeastern British Columbia.
Publication : European Geosciences Union General Assembly 2006. Vienna, Austria, April 02-07, 2006. Geophysical Research Abstracts
Issue : 8:
Page(s) : 00916.
Abstract
Large, rapid, low-gradient landslides are common in clay-rich sediments in northeastern British Columbia. The landslides block drainage in small watersheds in the region, creating upstream impoundments that may persist for years. We have documented such events in the Halden Creek watershed, 60 km southeast of Fort Nelson. The events are recorded geologically in two ways. First, trees are drowned in lakes dammed by the landslides and subsequently buried by deltaic sediments, where they are protected from decay. Bank erosion later exhumes the drowned trees. Second, landslide deposits with entrained wood are exposed along stream banks. We have reconstructed the recent history of landslide damming at Halden Creek by radiocarbon dating exhumed trees and wood in and beneath landslide deposits at 13 sites in the watershed. Drowned trees range in age from 169 +/- 59 to 274 +/- 49 14C yr BP. Wood in and below landslide deposits yielded radiocarbon ages ranging from modern to 965 +/- 49 14C yr BP. Greater dating precision has been obtained by wiggle matching and combining dates from cohorts of trees.
Bibliography of Canadian Geomorphology